PURPOSE: To prevent oxidation or decomposition of effective components, especially, a black-and-white developer, to retain effectivity of the developing soln. for a long term, and to prevent tar and sludge for a long term by processing development in the presensce of an aromatic primary amine type color developing agent, the black-and-white developer, and manganese salt and/or a cerium salt.

CONSTITUTION: A color developing agent is used generally in an concn. of 0.1W 30g, the black-and-white developer in 0.003W10g, and a manganese salt and a cerium salt in 0.1W20mg in terms of ions, all per liter of the developing soln. The use of only the color developing agent cannot achieve rapid development, and deteriorates storage stability. The use of a combination of said agent and the black-and-white developer can achieve rapid development, but deteriorates storage stability. The use of the agent and the manganese salt or the cerium salt improves storage stability but cannot achieve rapid development.